Crushing apparatus

ABSTRACT

A pair of arms (2a, 2b) is rotatably supported on a support through pins (8) at their intermediate portions. A front portion of each arm extending from the portion supported by the pin (8) to the distal end has a distal end formed into a fork comprising a plurality of prongs. The claws (7a, 7a&#39;, 7a, 7b, 7b) are attached on respective distal ends of these plural prongs. Only a specific claw (7a&#39;) of the claws (7a, 7a&#39;, 7a) of one arm (2a), having a pointed conical distal end, is positioned to protrude inward farther than the remaining claws (7a, 7a) and serves to generate deep and shallow cracks where it is forcibly applied to material to be crushed. Shearing blades (10a, 10a) are provided on the front portions of respective arms (2a, 2b) in the vicinity of the portions rotatably supported by the pins (8). Furthermore, a plurality of through holes (12) are formed in the intermediate portions of the front portions of respective arms except for the portion where the shearing blades are provided and the portion where the distal-end prongs are formed.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to an improvement of a crushing apparatusto be attached to a working machine such as a power shovel used forcollapsing wooden houses, concrete constructions, or the like.

BACKGROUND OF THE RELATED ART

A crushing apparatus designed to crush a structures by opening andclosing actions of arms operated by a hydraulic cylinder is alreadyknown publicly. This kind of crushing apparatus, for example, asdisclosed in the unexamined Japanese patent application JP-A-63-40061,is generally equipped with crushing blades, which is provided on therespective front ends of the arms to press and crush the concretestructure by opening and closing the arms, together with shearingblades, which are respectively provided closely to a pivot point of theintermediate portions of the arms, to shear reinforced steels, framesteels and the like exposed from the steel-reinforced concrete structurewhen they are crushed by the crushing blades.

However, broken pieces produced by crushing a structure are too large insize to be carried out of the site easily and to be subjected torecycling. Thus, the structure once crushed must be crushed again intosmaller fragments. In order to re-crush such broken pieces of oncecrushed structure, the crushing apparatus such as one described in theunexamined Japanese patent application JP-A-63-40061 is not suited,because such an apparatus is extremely inefficient for this purpose.

On the other hand, there are several known crushing apparatuses capableof crushing large size broken pieces into smaller pieces as disclosed inthe unexamined Japanese patent application JP-A-59-187976 andJP-A-4-347270. According to these prior art apparatuses, in each of thepaired arms, there are provided through holes at an intermediate portionof a front portion of the arm (i.e. a region extending from the pivotpoint of arms to the distal end thereof). Furthermore, one of thesepaired arms is provided with protrusions or rollers at its intermediateportion. Thus, the broken pieces, produced when the structure isdemolished, are scooped with these paired arms. Then, these brokenpieces are crushed further into smaller pieces with these paired armsclosing, while allowing the smaller broken pieces to pass through theabove-described through holes.

Demolition work of wooden houses or concrete structures is generallyclassified into the following categories:

(1) demolition of wooden or concrete columns, beams, and walls;

(2) crushing of concrete blocks produced by demolition of buildings intosmaller pieces;

(3) shearing of wooden beams and columns, or reinforced steels, or framesteels;

(4) collection of broken wooden pieces of beams and columns and sharedreinforced steels and frame steels produced by demolition of structure;and

(5) transportation of wooden fragments, reinforced steels, frame steels,concrete pieces and the like produced by demolition of structure onto aload-carrying platform of a truck or like vehicle.

When performing these works with various attachments selectivelyattached to a working machine such as a power shovel, a lot of time isrequired for replacing an attachment with another suitable for the nextwork and then a number of attachments are used, with the result that itis inefficient and uneconomical to perform such works. Meanwhile, in thecase where the crushing apparatus such as the one disclosed in thepreviously-described unexamined Japanese patent applicationJP-A-63-40061 suited for the demolition of structures is used, the abovedescribed work (1) can be performed efficiently, but other works (2),(4) and (5) cannot be carried out or can be carried out with extremelypoor efficiency. On the other hand, if the crushing apparatus such asthe one disclosed in the previously-described unexamined Japanese patentapplication JP-A-59-187976 or the unexamined Japanese patent applicationJP-A-4-347270 which is suited for the work for crushing broken piecesinto smaller pieces is used, the above classified works (2) through (5)can be performed effectively, but the most fundamental work (1) cannotbe carried out effectively due to lack of adequate power.

Although there are known attachments suited for the above-describe works(3) through (5), those are not suited for the above-described works (1)and (2).

DISCLOSURE OF INVENTION

An object of the present invention is to provide a crushing apparatuscapable of efficiently performing all of the above-described works (1)through (5) with a single crushing apparatus.

In order to accomplish the above and other related objects, one aspectof the present invention provides a crushing apparatus comprising: apair of arms, substantially identical in configuration and rotatablysupported by arm supports at their longitudinally intermediate portions,and an arm drive mechanism for simultaneously actuating rear ends of thepaired arms, to cause front portions of arms respectively extending fromthe portion supported by the arm support, to the distal end of the armto open and close, wherein the front portion of each arm has a shearingblade provided adjacent to the portion supported by the arm support toshear an object to be cut; a front edge divided into a fork having aplurality of prongs; a claw attached to each of the plural prongs; and aplurality of through holes opening in an intermediate region except forthe portion where the shearing blade is provided and the portion wherethe prongs are formed, and one of the paired arms has at least one clawprotruding inward farther than the remaining claws so that a front edgeof the farthest claw is positioned closer to the other arm than theremaining claws.

With the above arrangement, the present invention is capable ofperforming its functions in the following manner.

Of plural claws attached to respective prongs of one arm, a claw whosedistal end is positioned closest to the other arm is first brought intocontact with the structure. A pressing force is applied to the structurethrough this most protruding claw; therefore, the structure is subjectedto a concentrated force in the vicinity of that claw. This concentratedstress can easily cause deep and shallow cracks in the concretestructure. Subsequently, by closing the arms further in this condition,thereby causing other claws to bite into the structure for demolition ofa wider area.

The broken concrete pieces produced by the demolition of concretestructure are then pressed between intermediate portions of frontportions of the arms to be crushed into smaller pieces. The brokenpieces, crushed into smaller pieces, fall outside passing the throughholes opening in the intermediate portion of the front portion of eacharm.

The broken concrete pieces broken further into smaller pieces can bescooped by the distal end portion of the arm divided into a fork.Furthermore, longer size broken materials of columns, beams, reinforcedsteels, frame steels and the like, can also be collected by thisfork-shaped distal end of the arm.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view showing a crushing apparatus in accordancewith one embodiment of the present invention, wherein the front portionsof arms are opened;

FIG. 2 is a perspective view showing the same crushing apparatus as thatshown in FIG. 1 but viewed from a different direction;

FIG. 3 is a front view showing the crushing apparatus shown in FIG. 1wherein the front portions of a pair of arms are opened;

FIG. 4 is a front view showing the crushing apparatus shown in FIG. 1wherein the front portions of a pair of arms are closed; and

FIG. 5 is a side view (i.e. a partly cross-sectional view) showing thecrushing apparatus of FIG. 4, seen from the left of FIG. 4.

BEST MODE FOR CARRYING OUT THE INVENTION

A crushing apparatus 1, in accordance with one embodiment of the presentinvention, as shown in FIGS. 1 and 2, comprises a pair of arms 2a and 2bcooperatively pressing an object between front ends thereof, an armsupport 3 supporting the arms 2a and 2b so as to be freely opened orclosed, a working machine bracket 5 supporting the arm support 3rotatably, a hydraulic cylinder 4 attached to the working machinebracket 5, and a link mechanism 6 acting as an actuating forcetransmitting means linking a piston rod of the hydraulic cylinder withrear ends of the paired arm 2a and 2b.

Each of the paired arms 2a and 2b has an intermediate portion rotatablysupported about a pin 8 fixed on the arm support 3. A front portion ofeach arm, that is, a portion ranging from its intermediate part to itsdistal end, is bent inward, and its distal end is divided to form afork-like shape to provide a construction comprising a plurality ofprongs arranged along an axial direction of the pin 8. On the otherhand, a rear portion of each of the arm 2a and 2b, that is, a portionranging from its intermediate part to its rear end, is curved outward ata dull angle against the front portion.

The front portion of one arm 2a and the front portion of the other arm2b have the same lateral width (i.e. a length along the axial directionof the pin 8) in the vicinity of the pin 8 as shown in FIG. 5. However,the front portion of one arm 2a, except for the region around the pin 8,is formed to be wider than that of the other arm 2b.

A claw is attached to each tip of the prongs provided on the front endof the arms 2a and 2b. More specifically, as shown in FIGS. 1 and 2, onearm 2a has three prongs at the front end thereof. Claws 7a, 7a' and 7aare attached to these prongs, respectively, by welding or the like. Theother arm 2b has two prongs formed at its front end. Claws 7b and 7b areattached to these prongs by welding or the like.

Of three claws 7a, 7a' and 7a attached to the front end of the one arm2a, the centrally positioned claw 7a' protrudes more inward than theother two claws 7a and 7a do (that is, a protruding inclination of theclaw 7a' is closer to the normal line of the inside surface of the frontportion of the other arm 2b than that of the claw 7a). As a result, thecentral claw 7a' attached to the front end of the arm 2a come to bepositioned closer to the front portion of the other arm 2b than theother two claws 7a and 7a attached to laterally opposite front ends ofthe arm 2a. Note, as best seen in FIGS. 1, 2 and 3, that claw 7a' has apointed conical distal end.

Furthermore, there are provided a plurality of through holes on therespective front portions of the arms 2a and 2b at their intermediateregion excluding a region around the pin 8 supporting each arm and aregion around the prong tip attached with the claw. One arm 2a isprovided with a total of four through holes 11, by an arrangement of twoin a lateral direction and two in a longitudinal direction. Morespecifically, the portion having these four through holes 11 is thelaterally enlarged portion of the front portion of the one arm 2a. Theother arm 2b is provided with two through holes 11 along thelongitudinal direction thereof. As shown in FIG. 3, the through holes 11of one arm 2a and through holes 11 of the other arm 2b are located tocorrespond with each other in longitudinal direction but not laterally,since they are deviated from each other in lateral direction.Furthermore, as shown in FIG. 3 or 4, the through holes 11 positionednear the front ends of the arms 2a and 2b have a cross section which isgradually widened from the inside surface (pressing face) to the outsidesurface.

Furthermore, a cracking claw 9 is attached to the solid portion betweentwo laterally arranged through holes 11 and 11 in the one arm 2a bywelding or the like.

Moreover, a pair of shearing blades 10a and 10b is mounted on the frontportions of the respective arms 2a and 2b in the vicinity of the portionsupported by the pivot axis of the pin 8, to cut off reinforcing steels,frame steels or the like.

The arm support 3, as shown in FIGS. 1 and 2, has an upper end formedinto a ring flange 17. The arm support 3 is rotatably connected to theworking machine bracket 5 through the ring flange 17.

Each rear end of the arms 2a and 2b, rotatably supported on the armsupport 3 through the pin 8, is connected to one end of a connecting rod16 via a pin 30. The other end of the connecting rod 16 is connected toone end of a link piece 18 via a pin 40. The other end of the link piece18 is connected to the other connecting rod 18 via the pin 40. The linkpiece 18 has a central portion connected to the piston rod of thehydraulic cylinder 4. A pair of rollers 13 and 13 is provided on thislink piece 18, so that these rollers 13 and 13 can move in anup-and-down direction being guided by a guide hole 12 provided in thesupport 3. As a result, the movement of the piston rod connected withthe link piece 18 is restricted to that in the direction of the guidehole 12. With the above arrangement, the expanding or contracting motionof the piston rod of the hydraulic cylinder is converted, through thelink piece 18 and connecting rod 16, into the action where the rearportions of the arms 2a and 2b swing around the pins 8 respectively,eventually causing the front portions of the arms 2a and 2b to comeclose to or separate from each other.

The working machine bracket 5 supports the hydraulic cylinder 4.Mounting holes 19 and 20 provided in the working machine bracket 5 areused to attach the crushing apparatus 1 to a boom tip of a workingmachine. The crushing apparatus 1 is swingably supported around the boomtip of the working machine through one mounting hole 19. An actuator ofthe working machine, pivotally supported through the other mounting hole20, is expanded or contracted in order to enable the crushing apparatus1 to shift its portion around the mounting hole 19.

Now, a demolition work of concrete structure using the crushingapparatus 1 of the present invention will be explained.

The rotational angle of the arm support 3 with respect to the workingmachine bracket 5 is determined so that the paired arms 2a and 2b areset ready for holding fast the structure, such as concrete walls,columns or the like, from the direction normal to the longitudinaldirection of these structures. Thereafter, the structures are pressedbetween the claws 7a, 7a' and 7a provided on the front edge of the onearm 2a and the claws 7b and 7b provided on the front edge of the otherarm 2b, thereby crushing the structures. Since distal ends of a pair ofarms 2a and 2b are curved inward respectively, even when the structurecomes between the claws 7a, 7a' and 7a of arm 2a and claws 7b and 7b ofarm 2, the structure is still not caught fast between the arms 2a and2b, because the longitudinal intermediate portions of these arms arestill left open wide.

Of the three claws 7a, 7a' and 7a formed on the front portion of arm 2a,the centrally located claw 7a' has its pointed conical tip situatedcloser to the front portion of the other arm 2b than other two claws 7aand 7a do. Therefore, when the paired arm 2a and 2b are closed, thecentral claw 7a' of arm 2a first comes into contact with the structureprior to the claws 7a and 7a at a point between claws 7a and 7a. On theother hand, two claws 7b and 7b on the other arm 2b are simultaneouslybrought into contact with the construction. (Otherwise, the portionsnear the claws 7b and 7b is first brought into contact with theconstruction.)

If the arms 2a and 2b are further closed from this condition, thepointed conical tip of longer central claw 7a' of the one arm 2a bitesinto the structure, with a concentrated stress acting at this point. Asa result, the concrete structure will be cracked deep or shallow in thearea subjected to biting force of the claw 7a'. If the arms 2a and 2bare further closed from this condition, all of three claws 7a, 7a' and7a of the one arm 2a come into contact with the structures. Thus, thearea compressed by these claws is surely increased. As this stage, theconcrete structure has already become brittle due to the shallow anddeep cracks occurred therein, so that the actions of all the claws 7a,7a', 7a, 7b and 7b collaborate to facilitate crushing work.

As described above, one claw 7a' among a plurality of claws formed onone arm 2a is used to exert a concentrative force on a particular pointof concrete structure, causing the shallow and deep cracks to occur toweaken the structure at its point of contact, and then all the claws arecollaboratively used to compress the wider area of the weakenedstructure to be crushed.

After the concrete structure is crushed, many of reinforced steels,frame steels or the like are bared, which are then cut off by theshearing blades 10a and 10b provided on the front portions of the arms2a and 2b in the vicinity of the portion supported by the pin 8.

The broken pieces of the concrete produced by crushing the concretestructure is scooped with the arm 2 while the arms 2a and 2b are keptopen. Thereafter, the scooped broken pieces of structure is held withinthe curved surface of the one arm 2a, and the arms 2a and 2b are closedto compress the broken concrete pieces between the front portions ofrespective arms to break them further into smaller pieces. The frontportion of the one arm 2a, as shown in FIG. 5, is formed to have alaterally enlarged portion except for a part of the portion supported bythe pin 8. Therefore, broken pieces of concrete or the like can besmoothly scooped up by this laterally enlarged portion.

The broken concrete pieces pressed and crushed into smaller pieces bythe arms 2a and 2b pass the through holes 11 formed on the frontportions of the arms to fall outside of the clearance between arms 2aand 2b.

Especially, in the event that the demolition of concrete structureproduces relatively large concrete blocks, such large blocks can befurther broken by compressing them between confronting claws 7a, 7a', 7aand 7b, 7b as described previously.

On the other hand, when the broken concrete pieces are relatively small,they are held by the intermediate parts of the front portions of thearms 2a and 2b. Since the claw 9 is formed on the intermediate part offront portion of the one arm 2a, protruding toward the other arm 2b,this claw 9 first bites into the broken concrete pieces held between thecurved portions of the arms 2a and 2b in the process of closing the arms2a and 2b. Thus, the claw 9 exerts a concentrated force on a particularpoint on each of broken concrete pieces, thereby causing each concreteblock to be crushed easily into smaller pieces. In this manner, concreteblocks are further crushed into smaller pieces of predetermined size orless for recycling.

If the columns, walls, beams or the like of the concrete structures arenot so large, it will be sufficient to weaken and demolish thestructures by compressing them between the claws 7a' and 9 and the otherarm.

Furthermore, since not so large a force is required to demolish woodenhouses, it may be possible to crush their columns, beams and walls byclutching and compressing them between the intermediate portions of twoarms 2a and 2b.

Long size broken columns, beams, reinforced steels, frame steels and thelike, which are produced by demolishing and collapsing the structure tothe ground, can be scooped up with the arm 2a by opening the arms 2a and2b and moving the distal-end claws 7a and 7a of the arm 2a along thesurface of the ground. The distal end of the arm 2a is divided into afork and formed laterally wider than the distal end of the other arm 2b,and so these long size broken materials can be collected efficiently.

When moving long size materials such as columns, beams, reinforcingsteels and steel frame, collected and accumulated in the heap, toanother location, or when loading such materials on the bed of a truck,the intermediate parts of the front portions of arms 2a and 2b hold andcarry these long size broken materials. When releasing these long sizebroken materials, the other arm 2b is positioned slightly lower than thearm 2a. The claws 7b and 7b attached to the prongs of the arm 2b areidentical with each other in both configuration and protruding length,respectively providing a curved surface smoothly continuing from themain part of the front portion of arm 2b, thereby making it possible tosmoothly release the long size broken materials from the front portionof arm 2b without hitch.

Although the above-described embodiment discloses only one claw 9provided at the intermediate portion of the front portion of the one arm2a, a plurality of claws may be provided. Alternatively, this claw 9 maybe provided on the other arm 2b. Furthermore, as the arms 2a and 2b havetheir front portions curved inward as shown in FIGS. 1 and 2, theintermediate portions of the front portions of both arms 2a and 2b willnot come into contact with each other even if these arms 2a and 2b arecompletely closed, thus leaving a gap therebetween. For this reason, theclaw 9 provided at the intermediate portion of the front portion of onearm 2a acts so effectively that it can surely weaken the object comingbetween the intermediate portions of the front portions of arms 2a and2b.

However, the claw 9 need not be provided on one arm 2a, if the frontportions of the arms 2a and 2b are designed so that their confrontingsides come into contact fully with each other leaving no gaptherebetween when the arms 2a and 2b are completely closed. Even in sucha case, broken concrete pieces can further be crashed into smallerpieces between the solid sections of the front portions of the two arms,each of the solid section being located between through holes 11 in eachof the arms.

Still further, if the hydraulic cylinder 4 has a large output, aplurality of claws 7a, 7a' attached to one arm 2a can be arranged asfollows. Of these plural claws 7a, 7a', two or more claws 7a' - - - areprotruded inward farther than the remaining claws 7a - - - so that thedistal ends of these claws 7a' - - - are positioned closer to the frontportion of the other arm 2b than the distal ends of the remaining claws7a - - - .

I claim:
 1. A crushing apparatus, comprising:a pair of arms,substantially identical in shape, and rotatably supported on an armsupport at their respective longitudinally intermediate portions; and anarm drive mechanism for simultaneously actuating rear ends of said pairof arms to cause respective front portions of the arms, extending fromthe point where an arm is supported by said arm support to the distalend of the arm, to be opened and closed, wherein said front portion ofeach arm has a shearing blade provided adjacent to the portion supportedby said arm support to cut off an object to be cut, a distal end dividedinto a fork having a plurality of prongs, a claw attached to each ofsaid plural prongs, a plurality of through holes opening in anintermediate region other than the portion where said shearing blade isprovided and the portion where said prongs are formed, and one of saidpair of arms has at least one claw protruding inward farther than theremaining claws so that a distal pointed conical end of said at leastone claw is positioned closer to the other arm than the remaining claws.2. The crushing apparatus according to claim 1, wherein:said frontportions of said paired arms are curved inward respectively to presentclaw-shapes, and one or more claws are formed near the through holes inthe front portion of one arm to extend toward the front portion of theother arm.
 3. The crushing apparatus defined by claim 1, wherein:saidclaws attached to said prongs at the distal ends of each of said armsare identical with each other in both configuration and protrudinglength, and an inside surface of each claw provides one of a flat or acurved surface continuing to an inside surface of the front portion ofthe other arm.
 4. The crushing apparatus defined by claim 1,wherein:said front portion of one of said paired arms has a laterallyenlarged portion extending from the portion where said through holes areformed to the distal end thereof, which has a larger width than that ofthe remaining region.
 5. The crushing apparatus defined by claim 4,wherein:said front portion of the one arm having a laterally enlargedportion has three prongs formed at the distal end thereof, including acentrally formed prong which has a claw protruding inward farther thanclaws respectively attached to prongs located on both sides thereof sothat the central prong has a distal end positioned closer to the otherarm, and said front portion of the other arm has two prongs such thateach of these two prongs confront respective spaces between adjacent twoprongs of said three prongs formed on the front portion of said one arm.